Does Stone Removal Help Patients with Recurrent Urinary Tract Infections?

Purpose: We evaluated the impact of surgical extraction of nonobstructing asymptomatic stones on recurrent urinary tract infections and identified predictors of patients who may be rendered infection-free. Materials and Methods: We retrospectively reviewed charts to identify patients with recurrent urinary tract infections who underwent surgical stone extraction and were rendered stone-free. Demographic variables as well as procedure, infectious etiology, stone composition and the systemic inflammatory response syndrome rate were also recorded. Patients were divided into 2 groups. Group 1 had no evidence of recurrent infection following surgery while recurrent infection developed in group 2. Univariate analysis was performed using the Wilcoxon signed rank and Fisher exact tests. Logistic regression was used for multivariate analysis. Results: We identified 120 patients with recurrent urinary tract infections and a nonobstructive renal stone. Surgical management included shock wave lithotripsy in 32% of cases, ureteroscopy in 7% and percutaneous nephrolithotomy in 61%. Of the 120 patients 58 (48%) remained infection-free after surgery while 62 (52%) experienced recurrent infection. Factors associated with a higher risk of recurrent infections included type 2 diabetes mellitus (OR 1.73, p = 0.01), hypertension (OR 2.8, p = 0.007) and black ethnicity (OR 13.7, p = 0.009). Escherichia coli infections were more likely to resolve (OR 0.34, p = 0.01). In contrast, Enterococcus infections were more likely to persist (OR 2.5, p = 0.04). On multiple logistic regression analysis only race, hypertension and E. coli infections were significant predictors of infection clearance. Conclusions: Of patients with recurrent urinary tract infections and asymptomatic renal calculi 50% may be rendered infection-free following stone extraction. Patients with risk factors for recurrent infections after surgery should be counseled that stone extraction might not eradicate the infection.